Today, mobile phones are used by a large majority of people. They bring comfort and suppleness, and their functions and possibilities are increasing every day. We “wear” them with us all the day long. Another type of phone has appeared in the Internet world: the softphones, working on traditional workstations. These software based phones can be freely downloaded from the Internet, and allow each user connected to the web with it's workstation to call another user connected to the same softphone provider, or to traditional or IP phones. “Skype” for example is a well known company offering this kind of solution (http://www.skype.com/products/). The user audio interface of softphones is composed of two parts:                a microphone, and        a loudspeaker,both included in the workstation of the user. The user can also use a headset connected to the computer. In addition, conventional means such as the keyboard or a touch screen are used to interface the softphone for dialing or accessing some basic telephony functions (on-hold, call transfer, conferencing, etc . . . ). When the workstation is used as a telephone, the user has to speak in a built-in microphone of the laptop or computer, and listen through the built-in loudspeaker. Depending on the workstation, the quality of the microphone and loudspeaker may be variable. In any case, the user must stay close to the computer to use it as a phone.        
An object of the present invention is to replace the microphone and loudspeaker of the workstation by a real handset, which will be the mobile phone (e.g. a Global System for Mobile/General Packet Radio Service/Universal Mobile Telecommunications Systems (GSM/GPRS/UMTS) mobile phone). For this purpose, a short range wireless technology, such as the “Bluetooth” technology, can be used between the computer executing the softphone application and the mobile phone.
Another object of the present invention is to give the softphone application the possibility to “follow” the user with its mobile phone, going from a first workstation to another one by automatically activating a call transfer. The user is no longer required to stay seated close to the computer, but is able to move and to join any other computer running the softphone application.